High temperature tracers for downhole detection of produced water

ABSTRACT

A tracer composite comprises a tracer disposed in a metal-based carrier which comprises: a cellular nanomatrix and a metal matrix disposed in the cellular nanomatrix, wherein the tracer is detectable at a range of from about 1 ppt to about 1,000 ppm.

BACKGROUND

In a multi-zone oil and/or gas well, monitoring when water startsproducing and the flow rate of water in each zone are important tounderstand the dynamics of the wellbore. Tracers have been used in thepast to monitor water production in reservoirs. These tracers aretypically immobilized or integrated with a polymer carrier throughcovalent bonds or ionic interactions. Upon contact with water, thebinding between the tracers and the polymer carrier breaks thusreleasing the tracers. As oil and gas production activities continue toshift toward more hostile and unconventional environments, theperformance of the polymer-based tracer composites may be less thandesirable as the polymer carriers are susceptible to decomposition underharsh conditions. Accordingly the industry is always receptive to newtracer composites and improved methods for monitoring water productionin reservoirs.

BRIEF DESCRIPTION

The above and other deficiencies in the prior art are overcome by, in anembodiment, a tracer composite comprises a tracer disposed in ametal-based carrier which comprises: a cellular nanomatrix and a metalmatrix disposed in the cellular nanomatrix, wherein the tracer isdetectable at a range of from about 1 ppt to about 1,000 ppm.

An article comprising the tracer composite is also disclosed.

A method of analyzing water in a fluid produced from at least one zoneof a well comprises: introducing a tracer composite into the well;obtaining a sample of the fluid produced from at least one zone of thewell; and analyzing the tracer in the sample; wherein the tracercomposite comprises a tracer disposed in a metal-based carrier whichcomprises: a cellular nanomatrix and a metal matrix disposed in thecellular nanomatrix, wherein the tracer is detectable at a range of fromabout 1 ppt to about 1,000 ppm.

BRIEF DESCRIPTION OF THE DRAWINGS

The following descriptions should not be considered limiting in any way.With reference to the accompanying drawings, like elements are numberedalike:

FIG. 1 illustrates a tracer composite according to an embodiment of thedisclosure;

FIG. 2 illustrates a tracer composite wherein the tracer is uniformlydispersed in a metal-based carrier;

FIG. 3 illustrates an exemplary tracer composite comprising a core;

FIG. 4 illustrates an exemplary tracer composite comprising an outermember;

FIG. 5 illustrates a production well system for producing fluids frommultiple production zones;

FIG. 6 is a schematic illustration of a sand screen protected by aperforated shroud used in the production well system of FIG. 5; and

FIG. 7 illustrates the detection of different tracers from differentzones.

DETAILED DESCRIPTION

The inventors hereof have found that the temperature rating of tracercomposites can be greatly improved by incorporating tracers intodisintegrable metal-based carriers. The metal-based carriers are stablein the presence of hydrocarbons but can controllably dissolve in thepresence of water. Accordingly, when the tracer composites are incontact with produced water, the metal-based carriers dissolve at acontrolled rate releasing the tracers as a function of the concentrationof water and the environmental temperature. Compared with polymer-basedcarriers, metal-based carriers are much more stable thus cansignificantly enhance the temperature rating of the tracer composites.For example, while commercially available polymer-based tracercomposites typically have a temperature rating of about 350° F., thetracer composites of the disclosure can be used at a temperature of upto about 650° F. In addition, when the service function of the tracercomposites is complete, the metal-based carriers can completely dissolvewithout interfering with fluid production or other downhole operations.

Advantageously, the tracers are stable at temperatures up to about 650°F., up to about 600° F., up to about 550° F. or up to about 500° F.depending on the application and the specific tracers used. As a furtheradvantageous feature, the tracers can be detected with sensitivity up tothe order of part-per-trillion (ppt). In an embodiment, the tracer isdetectable at a range of from about 1 ppt to about 1,000 ppm, about 5ppt to about 1,000 ppm, or about 50 ppt to about 500 ppm. The tracers inthe tracer composites comprise one or more of the following: inorganiccations and/or inorganic anions; stable isotopes; activableelements/isotopes; or organic compounds.

The exemplary inorganic cations (also referred to as “characteristiccations”) include the cations of metals such as thorium, silver,bismuth, zirconium, chromium, copper, beryllium, cadmium, manganese,tin, rare earth metals, nickel, iron, cobalt, zinc, gallium, and thelike. As used herein, rare earth metals include scandium, yttrium,lanthanum, cerium, praseodymium, neodymium, promethium, samarium,europium, gadolinium, terbium, dysprosium, holmium, eribium, thulium,ytterbium, or lutetium. In an embodiment, the metals of thecharacteristic cations are distinct from the metals that may be presentin the formation so that it is clear that the detected characteristiccations are from the tracer composites instead of the formation.

Suitable inorganic anions (also referred to as “characteristic anions”)include complex cyanides such as dicyanoaurate complex ion Au(CN)₂ ⁻,tetracyanoickelate Ni(CN)₄ ²⁻, Co(CN)₆ ³⁻, Fe(CN)₆ ³⁻, nitrate, iodideand thiocyanate.

The characteristic anions and characteristic cations can be usedindependently. For example, the anions can be used in the form of saltslike sodium salts and potassium salts where the corresponding cationsare not characteristic cations. Alternatively, the characteristic anionsand characteristic cations can be used together as the tracer materials.Liquid chromatography and ion chromatography may be applied to elute thetracers and to improve the detectability of the tracers.

Stable isotopes in nitrates, ammonium salts, sulfates, carbonates canalso provide a unique signature. Exemplary isotopes include isotopes ofoxygen (¹⁶O, ¹⁸O), isotopes of nitrogen (¹⁴N, ¹⁵N), sulfur isotopes(³²S, ³⁴S, ³⁶S), carbon isotopes (¹²C, ¹³C), strontium isotopes (⁸⁶Sr,⁸⁷Sr), hydrogen isotopes (¹H, ²H), boron isotopes (¹⁰B, ¹¹B), orchlorine isotopes (³⁵Cl, ³⁷Cl).

The tracers can include activable tracers, which are nonradioactive butcan be activated by neutron radiation when needed, forming newgamma-emitting tracers. Advantageously, these tracers have a very shorthalf-life or decay very quickly. For example, the tracers can have ahalf-life less than about 30 days, less than about 15 days, less thanabout 2 days, or less than about 1 day. The activatable tracers can bediluted to reduce their level when activated. Suitable tracers include⁶⁹Ga(n, 2n)⁶⁸Ga, ¹²¹Sb(n, 2n)¹²⁰Sb, ¹³⁸Ba(n, 2n)¹³⁷mBa, ⁶³Cu(n, 2n)⁶²Cu.Other activatable tracers having a short half-life can also be used. Theactivable tracers can be activated right before sampling. For example,by selectively activating an activable tracer downhole in a particularzone or location, the information of water produced from that particularzone or location can be obtained. In this embodiment, the tracers fordifferent zones can be the same. Alternatively, the tracer can beactivated after a sample has been collected and before or when thesample is analyzed in a downstream location, for example on the ground.In this embodiment, the tracers for different zones can be different.

The tracers also include organic compounds. Certain aromatic acids andcompounds can be separated and detected with high sensitivity (ppb) byion chromatography and UV detection with significant aromatic character.Exemplary organic tracer compounds include pentafluorobenzoate;meta-trifluoromethylbenzoate; tetrafluorophthalate; 2,3-difluorobenzoicacid; 2,3-dimethylbenzoic acid; 2,4,6-trimethylbenzoic acid;2,4-difluorobenzoic acid; 2,4-difluorophenylacetic acid;2,4-dimethylbenzoic acid; 2,5-dimethylbenzoic acid;2,5-dimethylbenzenesulfonic acid; 2,6-difluorobenzoic acid;2,6-difluorophenylacetic acid; 2,6-dimethylbenzoic acid;3,4-difluorobenzoic acid; 3,4-dimethylbenzoic acid; 3,5-dimethylbenzoicacid; 3,5-di(trifluoromethyl)benzoic acid;3,5-di(trifluoromethyl)phenylacetic acid; 3-fluoro-4-methylbenzoic acid;4-ethylbenzenesulfonic acid; 4-ethylbenzenesulfonic acid;4-methylbenzenesulfonic acid; benzoic acid; benzenesulfonic acid;isophthalic acid; meta-fluorobenzoic acid; meta-fluorophenylacetic acid;meta-trifluoromethylbenzoic acid; meta-trifluoromethylphenylacetic acid;ortho-fluorobenzoic acid; ortho-trifluorophenylacetic acid;ortho-trifluoromethylbenzoic acid; ortho-trifluoromethylphenylaceticacid; phthalic acid; perfluorobenzoic acid; perfluorobenzenesulfonicacid; perfluorophenylacetic acid; para-fluorobenzoic acid;para-fluorophenylacetic acid; para-trifluoromethylbenzoic acid;para-trifluoromethylphenylacetic acid; or terephthalic acid.

Polyaromatic sulfonates have outstanding thermal stability and arestable at temperatures of up to about 650° F. or up to about 570° F.Exemplary sulfonates include 1,3,6,8-pyrene tetrasulfonate,1,5-naphthalene disulfonate, 1,3,6-naphthalene trisulfonate,2-naphthalene sulfonate, and 2,7-naphthalene disulfonate. Polyaromaticsulfonates can exhibit fluorescence. Their detectable concentration isin the parts per trillion (ppt) range by high performance liquidchromatography and fluorescence spectroscopy techniques.

The metal-based carriers in the tracer composites are metal compositesincluding a cellular nanomatrix and a metal matrix disposed in thecellular nanomatrix. The cellular nanomatrix comprises a nanomatrixmaterial. The metal matrix (e.g. a plurality of particles) comprises aparticle core material dispersed in the cellular nanomatrix. Theparticle core material comprises a nanostructured material. Such a metalcomposite having the cellular nanomatrix with metal matrix disposedtherein is referred to as controlled electrolytic metallic. An exemplarymetal composite and method used to make the metal composite aredisclosed in U.S. patent application Ser. Nos. 12/633,682, 12/633,688,13/220,832, 13/220,822, and 13/358,307, the disclosure of each of whichpatent application is incorporated herein by reference in its entirety.

The metal matrix can include any suitable metallic particle corematerial that includes nanostructure as described herein. In anexemplary embodiment, the metal matrix is formed from particle cores andcan include an element such as aluminum, iron, magnesium, manganese,zinc, or a combination thereof, as the nanostructured particle corematerial. More particularly, in an exemplary embodiment, the metalmatrix and particle core material can include various Al or Mg alloys asthe nanostructured particle core material, including variousprecipitation hardenable alloys Al or Mg alloys. More than one alloy canbe present in the metal matrix. For example, the metal matrix comprisesa plurality of particles wherein some of the particles are Al alloys andothers are Mg alloys. In some embodiments, the particle core materialincludes magnesium and aluminum where the aluminum is present in anamount of about 1 weight percent (wt %) to about 15 wt %, specificallyabout 1 wt % to about 10 wt %, and more specifically about 1 wt % toabout 5 wt %, based on the weight of the metal matrix, the balance ofthe weight being magnesium.

In an additional embodiment, precipitation hardenable Al or Mg alloysare particularly useful because they can strengthen the metal matrixthrough both nanostructuring and precipitation hardening through theincorporation of particle precipitates as described herein. The metalmatrix and particle core material also can include a rare earth element,or a combination of rare earth elements. Exemplary rare earth elementsinclude Sc, Y, La, Ce, Pr, Nd, or Er. A combination comprising at leastone of the foregoing rare earth elements can be used. Where present, therare earth element can be present in an amount of about 5 wt % or less,and specifically about 2 wt % or less, based on the weight of the metalcomposite.

The metal matrix and particle core material also can include ananostructured material. In an exemplary embodiment, the nanostructuredmaterial is a material having a grain size (e.g., a subgrain orcrystallite size) that is less than about 200 nanometers (nm),specifically about 10 nm to about 200 nm, and more specifically anaverage grain size less than about 100 nm. It will be appreciated thatthe nanocellular matrix and grain structure of the metal matrix aredistinct features of the metal composite. Particularly, nanocellularmatrix is not part of a crystalline or amorphous portion of the metalmatrix.

The cellular matrix includes aluminum, cobalt, copper, iron, magnesium,nickel, silicon, tungsten, zinc, an oxide thereof, a nitride thereof, acarbide thereof, an intermetallic compound thereof, a cermet thereof, ora combination comprising at least one of the foregoing.

The metal matrix can be present in an amount from about 50 wt % to about95 wt %, specifically about 60 wt % to about 95 wt %, and morespecifically about 70 wt % to about 95 wt %, based on the weight of themetal composite. Further, the amount of the metal nanomatrix material isabout 10 wt % to about 50 wt %, specifically about 20 wt % to about 50wt %, and more specifically about 30 wt % to about 50 wt %, based on theweight of the metal composite.

The metal composite can include a disintegration agent to control thedisintegration rate of the metal composite. The disintegration agent canbe disposed in the metal matrix, the cellular nanomatrix, or acombination thereof. According to an embodiment, the disintegrationagent includes a metal, fatty acid, ceramic particle, or a combinationcomprising at least one of the foregoing, the disintegration agent beingdisposed among the controlled electrolytic material to change thedisintegration rate of the controlled electrolytic material. In oneembodiment, the disintegration agent is disposed in the cellularnanomatrix external to the metal matrix. In a non-limiting embodiment,the disintegration agent increases the disintegration rate of the metalcomposite. In another embodiment, the disintegration agent decreases thedisintegration rate of the metal composite. The disintegration agent canbe a metal including cobalt, copper, iron, nickel, tungsten, zinc, or acombination comprising at least one of the foregoing. In a furtherembodiment, the disintegration agent is the fatty acid, e.g., fattyacids having 6 to 40 carbon atoms. Exemplary fatty acids include oleicacid, stearic acid, lauric acid, hyroxystearic acid, behenic acid,arachidonic acid, linoleic acid, linolenic acid, recinoleic acid,palmitic acid, montanic acid, or a combination comprising at least oneof the foregoing. In yet another embodiment, the disintegration agent isceramic particles such as boron nitride, tungsten carbide, tantalumcarbide, titanium carbide, niobium carbide, zirconium carbide, boroncarbide, hafnium carbide, silicon carbide, niobium boron carbide,aluminum nitride, titanium nitride, zirconium nitride, tantalum nitride,or a combination comprising at least one of the foregoing. Additionally,the ceramic particle can be one of the ceramic materials discussed belowwith regard to the strengthening agent. Such ceramic particles have asize of 5 μm or less, specifically 2 μm or less, and more specifically 1μm or less. The disintegration agent can be present in an amounteffective to cause disintegration of the metal composite 200 at adesired disintegration rate, specifically about 0.25 wt % to about 15 wt%, specifically about 0.25 wt % to about 10 wt %, specifically about0.25 wt % to about 1 wt %, based on the weight of the metal composite.

In metal composite, the metal matrix dispersed throughout the cellularnanomatrix can have an equiaxed structure in a substantially continuouscellular nanomatrix or can be substantially elongated along an axis sothat individual particles of the metal matrix are oblately or prolatelyshaped, for example. In the case where the metal matrix hassubstantially elongated particles, the metal matrix and the cellularnanomatrix may be continuous or discontinuous. The size of the particlesthat make up the metal matrix can be from about 50 nm to about 800 μm,specifically about 500 nm to about 600 μm, and more specifically about 1μm to about 500 μm. The particle size of can be monodisperse orpolydisperse, and the particle size distribution can be unimodal orbimodal. Size here refers to the largest linear dimension of a particle.

In an embodiment, the metal composite has a metal matrix that includesparticles having a particle core material. Additionally, each particleof the metal matrix is disposed in a cellular nanomatrix which is anetwork that substantially surrounds the component particles of themetal matrix.

As used herein, the term cellular nanomatrix does not connote the majorconstituent of the powder compact, but rather refers to the minorityconstituent or constituents, whether by weight or by volume. This isdistinguished from most matrix composite materials where the matrixcomprises the majority constituent by weight or volume. The use of theterm substantially continuous, cellular nanomatrix is intended todescribe the extensive, regular, continuous and interconnected nature ofthe distribution of nanomatrix material within the metal composite. Asused herein, “substantially continuous” describes the extension of thenanomatrix material throughout the metal composite such that it extendsbetween and envelopes substantially all of the metal matrix.Substantially continuous is used to indicate that complete continuityand regular order of the cellular nanomatrix around individual particlesof the metal matrix are not required. For example, defects in thecoating layer over particle core on some powder particles may causebridging of the particle cores during sintering of the metal composite,thereby causing localized discontinuities to result within the cellularnanomatrix, even though in the other portions of the powder compact thecellular nanomatrix is substantially continuous and exhibits thestructure described herein. In contrast, in the case of substantiallyelongated particles of the metal matrix (i.e., non-equiaxed shapes),such as those formed by extrusion, “substantially discontinuous” is usedto indicate that incomplete continuity and disruption (e.g., cracking orseparation) of the nanomatrix around each particle of the metal matrix,such as may occur in a predetermined extrusion direction. As usedherein, “cellular” is used to indicate that the nanomatrix defines anetwork of generally repeating, interconnected, compartments or cells ofnanomatrix material that encompass and also interconnect the metalmatrix. As used herein, “nanomatrix” is used to describe the size orscale of the matrix, particularly the thickness of the matrix betweenadjacent particles of the metal matrix. The metallic coating layers thatare sintered together to form the nanomatrix are themselves nanoscalethickness coating layers. Since the cellular nanomatrix at mostlocations, other than the intersection of more than two particles of themetal matrix, generally comprises the interdiffusion and bonding of twocoating layers from adjacent powder particles having nanoscalethicknesses, the cellular nanomatrix formed also has a nanoscalethickness (e.g., approximately two times the coating layer thickness asdescribed herein) and is thus described as a nanomatrix. The thicknessof the nanomatrix can be tuned during heat treatment by adjusting thetemperature and the duration that the coated powder particles areheated. In an embodiment, the nanomatrix has a thickness of about 10 nmto about 200 μm, or about 1 μm to about 50 μm. Further, the use of theterm metal matrix does not connote the minor constituent of metalcomposite, but rather refers to the majority constituent orconstituents, whether by weight or by volume. The use of the term metalmatrix is intended to convey the discontinuous and discrete distributionof particle core material within metal composite.

The tracers are present in an amount of about 1 to about 70 vol. %,about 2 to about 60 vol. %, or about 5 vol. to about 50 vol. % based onthe total volume of the tracer composites. Traces can be uniformlydispersed in the tracer composites. The tracer can be dispersed in themetal matrix, the cellular nanomatrix, or both. As used herein,“dispersed” means that the tracer is blended with the carrier on amicrometer size level and “dispersed” does not include doping such asadding a tracer in the atomic size level where the tracer is on thelattice sites of the carrier.

In an embodiment, the tracer composites further comprise a disintegrablecore. In another embodiment, the tracer composites further comprise anouter member disposed on a surface of the tracer composites. The outermember has a plurality of apertures to allow produced fluids to contactthe metal-based carrier. It is appreciated that the tracer compositescan include both a core and an outer member.

The core and the outer member can independently comprise one or more ofthe following: a disintegrable metal; a disintegrable metal alloy; or adisintegrable metal composite as disclosed herein. Exemplary materialsfor the tracer composite core include those consolidated or forged fromcoated particles having a core comprising Mg metal or an Mg alloy suchas Mg—Si, Mg—Al, Mg—Zn, Mg—Mn, Mg—Al—Zn, Mg—Al—Mn, Mg—Zn—Zr, or Mg— rareearth alloys, and a coating comprising one or more of the following: Al;Ni; Fe; W; Cu; or Co. Exemplary materials for the tracer composite corealso include Al, Zn, or Mn, alloyed with one or more of the following:Al; Mg; Mn; Zn; Cu; In; Ga; Si; Sn; or Pb. The materials for the outermember include those materials for the tracer composite core as well asnon-degradable materials. In an embodiment, the outer member of thetracer composites comprises steel. In an embodiment, the core and theouter member have a slower disintegrating rate than the metal-basedcarrier (metal composite) when tested at the same testing conditions.Alternatively, the core or the outer member can be formed from materialsthat are not disintegrable in downhole environments.

The materials for the core and the outer member can be stronger than thematerial for the metal-based carrier. Thus by including a core or anouter member, the structural integrity of the tracer composites can bemaintained.

Exemplary embodiments of the tracer composites are shown in FIGS. 1-4.Referring to FIG. 1, the tracer composite comprises cellular nanomatrix10 and metal matrixes 9 and 11. The metal matrices 9 and 11 can be thesame or different. In some embodiments, metal matrix 9 includesmagnesium alloys, metal matrix 11 includes aluminum alloys, and thecellular nanomatrix 10 includes Ni, Fe, Cu, W, Co, and the like.Although it is shown in FIG. 1 that the tracer 6 is disposed only inmetal matrix 11, it is appreciated that the tracer can be disposed inmatrix 9, the cellular nanomatrix 10, or both.

FIG. 2 shows that tracer 6 is uniformly distributed in a metal-basedcarrier 5. Referring to FIG. 3, the tracer composite further includes adisintegrable core 7. Referring to FIG. 4, the tracer composite canfurther include an outer member 8.

The tracer composites can be formed from a combination of, for example,tracers and powder constituents. The powder constituents include coatedparticles or a combination of coated particles and uncoated particles.The method includes compacting, sintering, forgoing such as by coldisostatic pressing (CIP), hot isostatic pressing (HIP), or dynamicforging. The cellular nanomatrix and nanomatrix material are formed frommetallic coatings on the coated particles. The chemical composition ofnanomatrix material may be different than that of coating material dueto diffusion effects associated with the sintering. The metal-basedcarrier (metal composite) also includes a plurality of particles thatmake up the metal matrix that comprises the particle core material. Themetal matrix and particle core material correspond to and are formedfrom the plurality of particle cores and core material of the pluralityof powder particles as the metallic coating layers are sintered togetherto form the cellular nanomatrix. The chemical composition of particlecore material may also be different than that of core material due todiffusion effects associated with sintering.

A method of analyzing water in a fluid produced from at least one zoneof a well includes: introducing a tracer composite into the well;obtaining a sample of the fluid produced from at least one zone of thewell; and analyzing the tracer in the sample.

The tracer composites can be incorporated into various downholearticles. As an example, a metallic tracer rod 2 made of the tracercomposite disclosed herein is installed between sandscreen 3 andprotecting shroud 4 as shown in FIG. 6. The sandscreen assembly 1 can beinstalled in a production well system for producing fluids from multipleproduction zones as shown in FIG. 5.

In an embodiment, the tracer composites are used in a well havingmultiple production zones. The tracer composites used can be unique foreach zones. For example, tracers in the trace composites disposed ineach zone have different chemical structures. Based on the amount ofmeasured tracers the amount of water flowing into the well at each zonecan be calculated. As illustrated in FIG. 7, the concentrations oftracers 1, 2, and 3 indicate the water production levels at zones 1, 2,and 3. In another embodiment, the tracers for different zones are thesame. When the water production information in a particular zone isneeded, the tracer in the trace composite of that zone can beselectively activated thus providing information of water production inthat zone.

Once a sample has been obtained, analysis for the presence andconcentrations of the selected tracers may be carried out. Suitableinstruments include, but are not limited to, gas chromatography (GC)using flame ionization detectors, electron capture detectors, and thelike; liquid chromatography (LC), infrared (IR) spectroscopy; massspectroscopy (MS); combination instrumentation such as Fourier transforminfrared (FTIR) spectroscopy, GC-MS, LC-MS, and the like. The tracer maybe detectable at a range of from about 1 ppt to about 1,000 ppm, about 5ppt to about 1,000 ppm, or about 50 ppt to about 500 ppm. Once thetracer concentration has been determined, the information may be used ina variety of ways. For example, the concentration of detected tracerscan provide information of the flow rate of produced water. Downholewater production detection and quantitative analysis method disclosedherein can be used for single zone or multiple zones for conventionaloil and gas, deepwater, unconventional oil and gas, and stream-assistedgravity drainage applications.

All ranges disclosed herein are inclusive of the endpoints, and theendpoints are independently combinable with each other. “Or” means“and/or.” “Optional” or “optionally” means that the subsequentlydescribed event or circumstance can or cannot occur, and that thedescription includes instances where the event occurs and instanceswhere it does not. As used herein, “combination” is inclusive of blends,mixtures, alloys, reaction products, and the like. “A combinationthereof” means “a combination comprising one or more of the listed itemsand optionally a like item not listed.” All references are incorporatedherein by reference.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the invention (especially in the context of thefollowing claims) are to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. Further, it should further be noted that the terms “first,”“second,” and the like herein do not denote any order, quantity, orimportance, but rather are used to distinguish one element from another.The modifier “about” used in connection with a quantity is inclusive ofthe stated value and has the meaning dictated by the context (e.g., itincludes the degree of error associated with measurement of theparticular quantity).

While typical embodiments have been set forth for the purpose ofillustration, the foregoing descriptions should not be deemed to be alimitation on the scope herein. Accordingly, various modifications,adaptations, and alternatives can occur to one skilled in the artwithout departing from the spirit and scope herein.

What is claimed is:
 1. A tracer composite comprising a tracer disposedin a metal-based carrier which comprises: a cellular nanomatrix having athickness of about 10 nanometers to about 200 micros; and a metal matrixdisposed in the cellular nanomatrix, the metal matrix comprisingparticles having a size of about 50 nanometers to about 800 microns andbeing surrounded by the cellular nanomatrix; and a tracer composite corewhich has a slower disintegrating rate than the metal-based carrier whenmeasured at the same testing conditions, the tracer and the metal-basedmatrix being disposed on a surface of the tracer composite core, and thetracer composite sore comprising a material that is consolidated orforged from coated particles having a particle core comprising magnesium(Mg) metal or a magnesium (Mg) alloy, and a coating comprising one ormore of the following: aluminum (Al), nickel (Ni), iron (Fe), tungsten(W), copper (Cu), or cobalt (Co); wherein the tracer is detectable at aminimum concentration of from about 1 part per trillion (ppt) to about1,000 parts per million (ppm) in a fluid produced from at least one zoneof a well, the tracer comprises one or more of the following: aninorganic anion, an isotope, an activatable element, or an organiccompound; and the metal-based carrier controllably releases the tracerin the presence of water in the fluid produced from at least one zone ofthe well.
 2. The tracer composite of claim 1, wherein the tracer ispresent in an amount of 1 to 70 volume percent (vol. %) based on thetotal volume of the tracer composite.
 3. The tracer composite of claim1, wherein the tracer composite further comprises an outer memberdisposed on a surface of the tracer composite.
 4. The tracer compositeof claim 3, wherein the outer member has a plurality of apertures. 5.The tracer composite of claim 3, wherein the outer member has a slowerdisintegrating rate than the metal-based carrier when tested at the sametesting conditions.
 6. The tracer composite of claim 1, wherein themetal matrix comprises magnesium; and the cellular nanomatrix comprisesone or more of the following: aluminum, calcium, cobalt, copper, iron,magnesium, molybdenum, nickel, silicon, zinc, or an intermetalliccompound thereof, and the metal matrix is compositionally different fromthe cellular nanomatrix.
 7. The tracer composite of claim 6, wherein themetal-based carrier further comprises a disintegration agent comprisingone or more of the following: cobalt; copper; iron; or nickel.
 8. Thetracer composite of claim 1, wherein the inorganic anion comprises oneor more of the following: Au(CN)₂ ²⁻; Ni(CN)₄ ²⁻, Co(CN)₆ ³⁻, Fe(CN)₆³⁻, NO₃ ⁻; I⁻; or SCN⁻.
 9. The tracer composite of claim 1, wherein theisotope comprises one or more of the following: ¹⁶O; ¹⁸O; ¹⁴N; ¹⁵N; ³²S;³⁴S; ³⁶S; ¹²C; ¹³C; ⁸⁶Sr; ⁸⁷Sr; ¹H; ²H; ¹⁰B, ¹¹B; ³⁵Cl, or ³⁷Cl.
 10. Thetracer composite of claim 1, wherein the activatable element comprisesone or more of the following: ⁶⁹Ga(n, 2n)⁶⁸Ga, ¹²¹Sb(n, 2n)¹²⁰Sb,¹³⁸Ba(n, 2n)¹³⁷mBa, or ⁶³Cu(n, 2n)⁶²Cu.
 11. The tracer composite ofclaim 1, wherein the tracer comprises one or more of the following:pentafluorobenzoate; meta-trifluoromethylbenzoate; tetrafluorophthalate;2,3-difluorobenzoic acid; 2,3-dimethylbenzoic acid;2,4,6-trimethylbenzoic acid; 2,4-difluorobenzoic acid;2,4-difluorophenylacetic acid; 2,4-dimethylbenzoic acid;2,5-dimethylbenzoic acid; 2,5-dimethylbenzenesulfonic acid;2,6-difluorobenzoic acid; 2,6-difluorophenylacetic acid;2,6-dimethylbenzoic acid; 3,4-difluorobenzoic acid; 3,4-dimethylbenzoicacid; 3,5-dimethylbenzoic acid; 3,5-di(trifluoromethyl)benzoic acid;3,5-di(trifluoromethyl)phenylacetic acid; 3-fluoro-4-methylbenzoic acid;4-ethylbenzenesulfonic acid; 4-ethylbenzenesulfonic acid;4-methylbenzenesulfonic acid; benzoic acid; benzenesulfonic acid;isophthalic acid; meta-fluorobenzoic acid; meta-fluorophenylacetic acid;meta-trifluoromethylbenzoic acid; meta-trifluoromethylphenylacetic acid;ortho-fluorobenzoic acid; ortho-trifluorophenylacetic acid;ortho-trifluoromethylbenzoic acid; ortho-trifluoromethylphenylaceticacid; phthalic acid; perfluorobenzoic acid; perfluorobenzenesulfonicacid; perfluorophenylacetic acid; para-fluorobenzoic acid;para-fluorophenylacetic acid; para-trifluoromethylbenzoic acid;para-trifluoromethylphenylacetic acid; terephthalic acid; 1,3,6,8-pyrenetetrasulfonate; 1,5-naphthalene disulfonate; 1,3,6-naphthalenetrisulfonate; 2-naphthalene sulfonate; or 2,7-naphthalene disulfonate.12. An article comprising the tracer composite of claim
 1. 13. Thecomposite of claim 1, wherein the tracer is dispersed in the metalmatrix.
 14. The composite of claim 1, wherein the tracer is dispersed inthe cellular nanomatrix.
 15. The composite of claim 1, wherein thecellular nanomatrix is continuous.
 16. A method of analyzing water in afluid produced from at least one zone of a well, the method comprising:introducing a tracer composite into the well; obtaining a sample of thefluid produced from at least one zone of the well; and analyzing thetracer in the sample; wherein the tracer composite comprises a tracerdisposed in a metal-based carrier which comprises: a cellular nanomatrixhaving a thickness of about 10 nanometers to about 200 microns and ametal matrix disposed in the cellular nanomatrix, the metal matrixcomprising particles having a size of about 50 nanometers to about 800microns and being surrounded by the cellular nanomatrix, a tracercomposite core which has a slower disintegrating rate than themetal-based carrier when measured at the same testing conditions, thetracer and the metal-based matrix being disposed on a surface of thetracer composite core, and the tracer composite sore comprising amaterial that is consolidated or forged from coated particles having aparticle core comprising magnesium (Mg) metal or a magnesium (Mg) alloy,and a coating comprising one or more of the following: aluminum (Al),nickel (Ni), iron (Fe), tungsten (W), copper (Cu), or cobalt (Co)wherein the tracer is detectable at a minimum concentration of fromabout 1 part per trillion (ppt) to about 1,000 parts per million (ppm)in the fluid produced from at least one zone of the well; and the tracercomprises one or more of the following: an inorganic anion, an isotope,an activatable element, or an organic compound.
 17. The method of claim16, wherein analyzing the tracer comprises determining the concentrationof the tracer using one or more of the following: gas chromatography(GC); liquid chromatography (LC); infrared spectroscopy (IR); massspectroscopy (MS); Fourier transform infrared spectroscopy (FT-IR);GC-MS; or LC-MS.
 18. The method of claim 16, wherein the tracercomposite is included in a downhole article.
 19. The method of claim 16,wherein separate tracer composites are included in separate downholearticles located at different zones of the well.
 20. The method of claim16, wherein the method further comprises determining the flow rate ofwater in the produced fluid.
 21. The method of claim 16, wherein themethod further comprises selectively activate the tracer of the tracercomposite disposed at a first zone of the well to analyze water in afluid produced from the first zone.